Patent GB-579829-A (GB)
Title: Automatic crank shaft grinding and polishing machines
IPC: B24B5/42
Filed: 1943-10-26
Abstract: 579,829. Grinding crank-shafts. WINONA TOOL MANUFACTURING CO. Oct. 26, 1943, No. 17641. Convention date, June 4. [Class 60] A machine for grinding the main and rod bearings of crank-shafts comprises chuck shafts between which the crank-shaft is mounted and by which it is rotated and reciprocated axially, the bearings being ground by the flat end face of a grinding wheel, and polished by a buffing band. The machine comprises a frame built up of supports 15, 16, Fig. 1, to which'is secured a hollow cap piece 17. At one end of the frame a bracket 30, Fig. 6, is mounted, adjustable along the piece 17, by an angled bolt 37, plate 41 and a wing nut 42 and in a boss 44 on the bracket is a long bearing 45 for a chuck shaft 46 with a chuck head 52 a similar bracket 51 also is mounted on the piece 17 and carries a'chuck shaft 50 with a chuck head 53, the crank-shaft 54 being held by the chucks. The shaft 46 is driven by a belt 59 from a motor 61 mounted on a bracket 64. Supported on the members 15, 16 by keepers 28, 29, is a shaft 27 and on the shaft is slidably and rotatably mounted a boss 66 secured to a plate 65 over which is longitudinally slidable a bar 68 of rectangular section guided at its side faces by rollers 70, Fig. 4, and held down on the plate by a keeper 69 ; the bar may be of square section and guided on all of its faces by rollers. The bar 68 has thereon bosses 75, 76 in which is slidable a.. shaft 77, which passes through a boss 79 on a member 80 within which is a shaft 81 carrying a grinding- wheel 82 having an end operative face 83: The shaft 77 has an extension 78 provided with an adjustable hook-member 84 which, by means of rollers 85, 86, bears on the crank-shaft bearing 57, shown as a rod bearing, being ground ; a compression spring 89 between a collar 90 fast on the shaft 77 and a second collar 91 resting on a boss 92 on the member 80, together with a thumb nut 87 serves to apply the wheel 82 to the shaft bearing with the desired pressure. The shaft 81 is rotated by a motor 102 mounted on the member 80. The shaft 25 has slidable thereon a bearing 93 secured to a plate 94 carrying a motor 95, which through belting 97 drives a polishing belt 101 extending over a crank shaft bearing. In order to effect the axial reciprocation of the chuck shafts 46, 50 and of the crank-shaft, a gear case 104, Fig. 13, is provided having in its back wall 105 a boss 106 to receive the end of shaft 50, and at the front a cover 109. The shaft 50 has an axial extension 112 coupled rotatably with a threaded shaft 115 by screws 154, Fig. 14, engaging a circumferential groove 153 in the shaft extension 112, the shaft 115 having a bearing at 116 in the cover 109. A swinging block 120, Fig. 8, is provided, having therein half threads and may be locked in engagement with the shaft 115 by a'bolt 121 in an arm 122 carried by a rod 124 on the bracket 51 ; rotation of shaft 115 thus will cause axial movement thereof together with the gear case 104 and shaft 50. The shaft 115 is rotated by a gear 146 rotatably mounted on the extension 112 and having thereon a pin 147 to engage a pin 148 in shaft 115, the gear 146 being rotated in opposite directions by engaging therewith one or other of two engaging gears driven by chain gearing from the extension 112 and carried on spindles mounted on a block coupled by a pin 131 to a block 133 transversely slidable on the wall 105 of gear case 104, and held normally in central position with the gears disengaged, by springs 177. The block 133 is coupled to the armatures of two solenoids the circuits of which include holding relays 169, 169<1>, Fig. 17, having contacts 174, 174<1> adapted to be engaged at the ends of the axial strokes of the crank-shaft &c, by contacts 173, 173<1> on coupled fingers 167, 167<1> pivoted to and insulated from a plate adjustably pivoted on a stand, The lower ends of the fingers 167, 167<1> lie in the path of reciprocation of the crank cheeks 151, 152 and at the ends of the strokes thereof are moved to make one of the contacts 173, 174 and 173<1>, 174<1> and break the other, the solenoids thus becoming energized alternately to move the block 133 and reverse the reciprocation of the shaft. In a modified form, as employed for grinding the rod bearings, the rod 77 is replaced by a rod of square section, to prevent angular movement, the rod carrying an extension 207, Fig. 18 to which the hook member 208, which has a part 210 adjusted by a spring 211, is secured ; the extension 207 also carries the relays, contacts and fingers, as described above, for reversing the axial movement of the shaft. T he grinding face of the wheel 82 is'adjusted into parallelism with the shaft axis by adjustment of one end of the shaft 27 by means of the adjustable keeper 29. In order to prevent sag of the crank-shaft, an electromagnet is provided, acting upon one of the main bearings. This magnet is carried by a member 190, Fig. 15, adjustably secured to the piece 17 and is energized by a coil 195 ; the armature 197 has thereon rollers 198 to engage the bearing, and slight adjustment is provided by means of slits cut in the member 190 adapted to be closed or allowed to open by adjustment of screws. U.S.A. Specifications 2,130,003 and 2,297,344 are referred to.